Ice Drill

ABSTRACT

A tool for drilling holes through ice has a central drill rod ( 2 ) having a spiral ( 5 ) for lifting crushed ice formed by the drilling, a carrier ( 6 ) attached to one end of the drill rod ( 2 ) and being fixed to at least one cutting blade ( 12 ) extending substantially radially with respect the drill rod ( 2 ) and having a cutting edge ( 13 ) for cutting and thereby drilling into the ice upon rotation of the drill rod ( 2 ). A member is fixed with respect to the carrier ( 6 ) for support on the ice through a surface ( 15 ) at a distance in the direction of the axis of the drill rod ( 2 ) in the drilling direction behind the cutting edge of the cutting blade ( 12 ) for defining the cutting depth when drilling by the tool.

FIELD OF THE INVENTION AND PRIOR ART

The invention relates to a tool for drilling a hole through thick outdoor ice, on lakes and the like, which comprises a central drill rod having a spiral therearound for lifting crushed ice formed by the drilling, a carrier attached to one end of the drill rod and having fixed thereto at least one cutting blade extending substantially radially with respect to the drill rod and having a cutting edge for cutting and thereby drilling into the ice upon rotation of the drill rod.

Such a tool is normally called ice drill, for what reason this expression will be used hereinafter.

Outdoor ice means ice on lakes, rivers, oceans and the like, where a flowing water is present under the ice.

Such an ice drill is normally used for making holes through ice for fishing, such as jigging, but other intensions of the hole production is also possible. Such ice drills may be designed to make holes with varying diameters, in which a typical diameter for such a hole is about 20 cm.

Such ice drills may be adapted to be driven to rotate by hand through any type of crank, but they may also be equipped with a motor for rotating the drill rod.

Such an ice drill has normally two said cutting blades arranged with a spacing of 180° about the drill rod, but the invention is not restricted thereto, but also one single cutting blade or more than two cutting blades are possible.

The ice drills known until now have a tendency to occasionally treat the ice irregularly and deliver uncomfortable hits and pulls to the arm of the person drilling by means of the ice drill or holding it. This problem varies depending upon the nature of the ice, and it may for some ice be experienced as very uncomfortable and irritating to have the irregular operation of the cutting blades and the drill when drilling. This makes the boring more difficult and makes the person carrying out the drilling tired. This problem gets greater the more holes are to be drilled on one day and the thicker the ice. It may here well be a question of an ice thickness of up to 1 m, and it is not unusual that at least 10 holes are drilled per fisher (jigger) in one fishing day.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a tool of the type defined in the introduction, which is in at least some aspect improved with respect to such tools already known.

This object is according to the invention obtained by providing such a tool in front of each said cutting blade with respect to the rotation direction of the drill rod intended for drilling with a member fixed with respect to said carrier and having a surface for supporting upon the ice when boring at a distance in the direction of the axis of the drill rod in the drilling direction behind the cutting edge of the cutting blade for defining the cutting depth when drilling by the tool.

By arranging such a support surface in connection with the cutting blade, preferably in the intended direction of rotation substantially directly in front of the cutting blade, the cutting depth will be well defined when drilling, so that an even and fine operation is obtained when drilling through the ice, without uncomfortable hits and pulls in the arm for very different ice types. This means also that the very drilling gets less tiring.

According to a preferred embodiment of the invention, the tool comprises an arrangement for adjusting said distance between the support surface and the cutting edge defining the cutting depth. This makes it possible to adjust the cutting depth when drilling to the one being most suitable for exactly the ice type in which it is drilled for the moment. Thus, the cutting depth may be adjusted to be smaller for ice being more difficult to penetrate than otherwise and the resistance to rotating the drill may be reduced to a desired level.

According to a preferred embodiment of the invention such an arrangement comprises means for exchangeably fixing said carrier with respect to the drill rod for alternating between carriers having different said distances between cutting edge and support surface. This means that it will be easy to obtain a change between cutting depths well defined in advance.

According to another preferred embodiment of the invention the arrangement comprises means for adjustably fixing the cutting blade on the carrier in different positions corresponding to different said distances between the cutting edge and said support surface. This means that the cutting depth may be changed without changing any carrier, which may be advantageous in some situations. It is also possible that said two possibilities to adjust the distance defining the cutting depth may be combined on the tool.

According to another preferred embodiment of the invention the carrier comprises a ring concentric with respect to the axis of the drill rod and having such a diameter that the cutting blade extends by the end thereof remote with respect to the drill rod radially outside the ring.

By arranging such a ring the smoothness of the drilling is improved further, since it means that the drilling will be smooth to the last cutting blade, i.e. until the ice is completely penetrated. Another advantage of the existence of the ring is that it gets possible to drill “hole in hole”, i.e. to drill one hole which will partly be located in a hole already existing in the ice. This has so far not been possible, since the drill has in such a case been pushed away from the desired drilling position when a cutting blade has hit the wall of the hole already existing. In particular when the ring, such as in another preferred embodiment of the invention, is combined with a central tip extending axially at one end of the drill rod, which is arranged to project in the axial direction beyond the cutting blade or the cutting edges of the cutting blade so as to be pressed down into the ice when drilling, “hole in hole” may be comfortably drilled.

According to another preferred embodiment of the invention said support member is arranged on the ring or is a part thereof. A definition of the cutting depth is in this way easily and reliably obtained.

According to another preferred embodiment of the invention said carrier has the character of a bore crown which also comprises said member providing a support surface. It is then advantageous if an attachment fixed to the drill rod is there for removably fixing the bore crown to the drill rod.

According to another preferred embodiment of the invention the bore crown, except for the cutting blades thereof, is substantially made of a plastic material. Thanks to the arrangement of a carrier in the form of a said ring as bore crown it will be possible to design this of plastic material, which results in several advantages. It will for instance be easier to produce an attachment for cutting blades allowing exchange of the cutting blade by the fact that it may be snapped on or the like through said attachment. It will also be possible to manufacture such a bore crown of plastic material in larger series to an attractive cost per unit.

According to another preferred embodiment of the invention said spiral is together with a sleeve being central with respect thereto moulded into one piece of a plastic material, and the sleeve receives and is secured to a rigid drill rod extending therethrough, preferably of metal. The completely unique about making a spiral on an ice drill of plastic material means a considerable saving of weight with respect to conventional ice drills having a spiral of steel. This is an important advantage, since the ice drills are often carried along by hand or are attached to a rucksack or the like. Furthermore, a spiral of this type may be manufactured in larger series to a lower cost than a steel spiral which has to be welded to the drill rod. Another advantage is that the manufacturing accuracy of the spiral may be increased.

According to a further preferred embodiment of the invention said distance between the support surface and the cutting edge is 5-40 mm, advantageously >10 mm and preferably 10-30 mm. It has been found that an adjustment of the cutting depth by selecting said distance within these intervals results in a smooth drilling by means of the tool according to the invention.

Further advantages as well as advantageous features of the invention appear from the following description and the other dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings below follows a specific description of preferred embodiments of the invention cited as examples. In the drawings:

FIG. 1 is a side elevation of an ice drill according to a preferred embodiment of the invention,

FIG. 2 is an enlarged partially exploded view of the ice drill according to FIG. 1,

FIG. 3 is a further enlarged view of the lower end of the ice drill according to FIG. 1,

FIG. 4 is a perspective view obliquely from above of the lower end of the ice drill according to FIG. 1,

FIG. 5 is a view corresponding to FIG. 4, but obliquely from below, of a variant of the ice drill according to FIG. 1,

FIG. 6 is a view corresponding to FIG. 3 of an ice drill according to the invention having a bore crown exchanged with respect to FIG. 3,

FIG. 7 is a view corresponding to FIG. 3 of an ice drill according to the invention with another bore crown with respect to FIG. 3 and FIG. 6, and

FIG. 8 illustrates how “hole in hole” may by reliably drilled to an ice drill according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

An ice drill 1 according to an embodiment of the present invention is illustrated in FIG. 1. This has a central rigid drill rod 2, which for example is made of stainless steel or surface treated steel. A crank 3 is removably secure to the drill rod at 4 so as to be able to drive the drill rod 2 to rotate around the axis thereof.

A spiral 5 extends around the drill rod from the region of a bore crown 6 and upwards for lifting crushed ice formed by the drilling. The spiral 5 is in the present case moulded of plastic material in one single piece with a sleeve 7 central with respect thereto. It is illustrated in FIG. 2 how this piece moulded of plastic is moved onto the drill rod upon manufacturing thereof to the position according to FIG. 1, where a recess 8 in the spiral receives a projection 9 extending from the drill rod and the spiral is then shrank onto the drill rod 2. By the manufacture of the spiral 5 in this way of plastic material it gets an advantageous very low weight. A suitable material for the spiral is nylon having short glass-fibres, which gives a soft material being attractive from the cost point of view. Another possibility is to put the tube forming the drill rod in the extruder and extrude the spiral directly onto the tube. The spiral will then be secured to the tube by shrinking when the plastic material is cooled down.

For a hand driven ice drill it is also conceivable to manufacture also the tube forming the drill rod of plastic at the same time as the spiral in one single piece. A harder plastic material should in such a case be used, such as polyurethane having long glass-fibres.

Reference is now also made to FIG. 3. A carrier 10 in the form of a bore crown moulded of plastic material is through means 11, such as screws and nuts as well as an attachment 22 fixed to the drill rod, removably fixed to the drill rod in the lower region thereof. A hard plastic material is required for the bore crown, such as the hard and tough material polyurethane with long glass-fibres. This carrier 10 carries two cutting blades 12 extending substantially radially with respect to the drill rod and having a cutting edge 13 for cutting and thereby drilling into the ice upon rotation of the drill rod. The member 14, here a heel, fixed with respect to the carrier is arranged in the rotation direction for the drill rod intended for drilling in front of each said cutting blade, which has a surface 15 for supporting on the ice when drilling arranged on a distance in the direction of the axis of the drill rod in the drilling direction behind the cutting edge of the cutting blade for defining the cutting depth when drilling by the ice drill. This cutting depth is in FIG. 3 indicated by D. Thus, this cutting depth is defined as the vertical distance between the cutting edge 13 of the cutting blade 12 and the support surface 15 running in front of the cutting edge when rotating the drill rod with bore crown when drilling vertical holes. This distance is preferably in the order of 5-40 mm, but also other distances are conceivable and the distance most suited is inter alia dependent upon the nature of the ice and the diameter of the holes to be drilled.

The carrier 10, i.e. the bore crown, comprises in this case a ring 16 concentric with respect to the axis of the drill rod (see also FIGS. 4 and 5) and having such a diameter that the two cutting blades 12 extend with the end 17 thereof remote to the drill rod radially outside the ring, so that this ring may move down into the hole being bored through the movement of the cutting blades around the axis of the drill rod. The support member 14, i.e. the heel, is here formed by an integrated part of the ring itself, which is moulded of plastic material. Thanks to the use of such a ring as carrier it gets possible to mould it of plastic material, which results in advantages, especially with respect to the possibility to arrange attachments for the cutting blades on the carrier.

A central tip 18 extending axially is arranged at the lower end of the drill rod to extend in the axial direction beyond the cutting edges of the cutting blades for being pressed into the ice when drilling. Such a tip generates for sure a certain resistance to rotation of the drill rod upon drilling, but it is particularly advantageous in combination with a ring according to the invention, since this offers advantages to be discussed further below with reference to FIG. 8.

It is illustrated in FIG. 5 how the cutting depth may be adjusted between different positions when drilling by displacing the attaching members 19 for the cutting blades 12 in grooves 20 of the attachment on the bore crown, so that said distance between the support surface 15 and the cutting edge 13 of the respective cutting blade may be adjusted.

Another possibility to such an adjustment is illustrated in FIG. 6, i.e. here the bore crown is exchanged by another bore crown through loosening the attaching members 11. An exchange to a bore crown having half the distance between the support surface 15 and the cutting edge 13 with respect to the bore crown in FIG. 3 has,here taken place, so that the cutting depth will be half as great when drilling.

Another possible design of the bore crown of an ice drill according to the present invention is illustrated in FIG. 7, and the ring has here no heels 14 and the support surface is instead formed by a substantially circumferential surface 21 of the ring directed axially.

The function of the ice drill according to the invention is as follows. When a hole is to be drilled into an ice the tip 18 is placed on the location where the hole is to be drilled, and the drill rod is rotated, either by a crank 3 according to FIG. 1 or by a motor. The support surface 15 and 21, respectively, of the bore crown will then form a support at the same time as the distance between this and the cutting edge 13 in the direction of the axis of the drill rod will determine the cutting depth. The drilling will in this way be smooth and comfortable all the way until the ice has been completely penetrated. Crushed ice will as usual be lifted through the spiral.

“Hole in hole” may efficiently be drilled thanks to the combination of the tip 18 and the ring 16, which is illustrated in FIG. 8. This means that the hole is drilled so that it extends slightly into a hole already existing. This has not been possible by using conventional ice drills having no said ring, since this means that they get a too bad support for maintaining the drill rod in the position thereof when the cutting edge of a cutting blade hits the wall surface of the hole already existing when drilling.

Another advantage of the ring is that it constitutes a protection against the risk that the person handling the drill will drill into his own foot.

The invention is of course not in any way restricted to the preferred embodiments shown above, but many possibilities to modifications thereof will be apparent to a person with skill in the art without departing from the basic idea of the invention as defined in the appended claims.

It is for instance in the case of using another material then plastic, such as steel, possible to have something else than a ring as carrier for the members providing support surfaces, although a ring is advantageous for a good stability when drilling.

The cutting blades may also be exchangeable by cutting blades having a different design, especially depth (=width), so as to change the cutting depth of the ice drill.

The fact that the member providing support surface is fixed with respect to the carrier does not mean that it has to be a part of the carrier or be attached thereto. It may be completely separated from the carrier.

There may also be more than one said carrier for cutting blades, such as a separate one for each cutting blade.

It is also conceivable to mould the bore crown as well as the drill rod and the spiral into one and the same piece, then of a harder plastic material, such as polyurethane having long glass-fibres. 

1. A tool for drilling holes through thick outdoor ice on lakes and the like, which comprises a central drill rod (2) having a spiral (5) therearound for lifting crushed ice formed by the boring, a carrier (6) attached to one end of the drill rod and having fixed thereto at least one cutting blade (12) extending substantially radially with respect to the drill rod and having a cutting edge (13) for cutting and thereby drilling into the ice upon rotation of the drill rod, and in front of each said cutting blade with respect to the rotation direction of the drill rod intended for drilling, a member (14) fixed with respect to said carrier and having a surface (15) for supporting upon the ice when drilling at a distance in the direction of the axis of the drill rod in the drilling direction behind the cutting edge of the cutting blade for defining the cutting depth when drilling by the tool.
 2. A tool according to claim 1, additionally comprising an arrangement for adjusting said distance between the support surface and the cutting edge defining the cutting depth.
 3. A tool according to claim 2, wherein said arrangement comprises means (11) for exchangeably fixing said carrier (6) with respect to the drill rod (2) for alternating between carriers having different said distances between cutting edge (13) and support surface (15).
 4. A tool according to claim 2, wherein said arrangement comprises means (19, 20) for adjustably fixing the cutting blade (12) on the carrier in different positions corresponding to different said distances between the cutting edge (13) and said support surface (15).
 5. A tool according to claim 1, wherein the carrier comprises a ring (16) concentric with respect to the axis of the drill rod and having such a diameter that the cutting blade (12) extends by the end (17) thereof remote with respect to the drill rod radially outside the ring.
 6. A tool according to claim 5, wherein said support member (14) is arranged on the ring or is a part thereof.
 7. A tool according to claim 5, wherein said support member is formed by a heal-like piece (14) arranged on the ring (16) and projecting further in said drilling direction than the rest of the ring.
 8. A tool according to claim 5, wherein said member is formed by a substantially circumferential surface (21) of the ring (16) directed axially.
 9. A tool according to claim 1, wherein said carrier (6) has the character of a bore crown also comprising said member providing a support surface.
 10. A tool according to claim 9, additionally comprising an attachment (22) fixed to the drill rod (2) for removably fixing the bore crown (6) to the drill rod.
 11. A tool according to claim 5, wherein said carrier (6) has the character of a bore crown also comprising said member providing a support surface, and the bore crown (6), except for the cutting blades thereof, is made substantially of plastic material.
 12. A tool according to claim 1, wherein said spiral (5) is moulded by a plastic material in one piece with a sleeve (7) central with respect thereto, and the sleeve receives and is secured to a rigid drill rod extending therethrough, preferably of metal.
 13. A tool according to claim 1, wherein said spiral (5) is moulded of a plastic material in one piece with a tube forming the drill rod.
 14. A tool according to claim 9, wherein said spiral (5) is moulded of a plastic material in one piece with a tube forming the drill rod and the bore crown.
 15. A tool according to claim 5, wherein a central tip (18) extending substantially axially is arranged at one end of the drill rod to project in the axial direction beyond the cutting blade or the cutting edges (13) of the cutting blade to be pressed down into the ice upon drilling.
 16. A tool according to any claim 1, wherein said distance between the support surface (15, 21) and the cutting edge (13) is 5-40 mm, advantageously ≧10 mm and preferably 10-30 mm.
 17. A tool according to claim 3, wherein said arrangement comprises means (19, 20) for adjustably fixing the cutting blade (12) on the carrier in different positions corresponding to different said distances between the cutting edge (13) and said support surface (15).
 18. A tool according to claim 6, wherein said support member is formed by a heal-like piece (14) arranged on the ring (16) and projecting further in said drilling direction than the rest of the ring.
 19. A tool according to claim 2, wherein the carrier comprises a ring (16) concentric with respect to the axis of the drill rod and having such a diameter that the cutting blade (12) extends by the end (17) thereof remote with respect to the drill rod radially outside the ring.
 20. A tool according to claim 3, wherein the carrier comprises a ring (16) concentric with respect to the axis of the drill rod and having such a diameter that the cutting blade (12) extends by the end (17) thereof remote with respect to the drill rod radially outside the ring. 